We make a 2-D transient analysis of field-plate AlGaN/GaN HEMTs with a semi-insulating buffer layer, where only a deep acceptor above the midgap is considered. The deep-acceptor density is varied between 1017 cm-3and 8 × 1017 cm-3. It is studied how the deep-acceptor density and the field plate affect the buffer-related drain lag and gate lag, and current collapse. It is shown that the lags and current collapse are reduced by introducing a field plate. This reduction occurs because electron trapping by the deep acceptors is weakened by the field plate. It is also shown that without a field plate, the drain lag and current collapse increase with increasing the deep-acceptor density as expected, although the gate lag decreases when the deep-acceptor density becomes high in the region between 2 × 1017 cm-3and 8 × 1017 cm-3. On the other hand, with a field plate, surprisingly, the lags and current collapse decrease when the deep-acceptor density becomes high. This is attributed to the fact that the reduction in drain lag and current collapse by introducing a field plate becomes more significant when the deep-acceptor density becomes higher.
|ジャーナル||IEEE Transactions on Device and Materials Reliability|
|出版ステータス||Published - 2018 3月|
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